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From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: kvm@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>,
	Siddharth Chandrasekaran <sidcha@amazon.de>,
	linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org
Subject: [PATCH RFC 15/22] KVM: x86: hyper-v: Honor HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE privilege bit
Date: Tue, 13 Apr 2021 14:26:23 +0200	[thread overview]
Message-ID: <20210413122630.975617-16-vkuznets@redhat.com> (raw)
In-Reply-To: <20210413122630.975617-1-vkuznets@redhat.com>

Synthetic debugging MSRs (HV_X64_MSR_SYNDBG_CONTROL,
HV_X64_MSR_SYNDBG_STATUS, HV_X64_MSR_SYNDBG_SEND_BUFFER,
HV_X64_MSR_SYNDBG_RECV_BUFFER, HV_X64_MSR_SYNDBG_PENDING_BUFFER,
HV_X64_MSR_SYNDBG_OPTIONS) are only available to guest when
HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE bit is exposed.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/kvm/hyperv.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 0678f1012ed7..1299847c89ba 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -312,7 +312,9 @@ static int syndbg_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data, bool host)
 {
 	struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
 
-	if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
+	if (unlikely(!host && (!kvm_hv_is_syndbg_enabled(vcpu) ||
+			       !(to_hv_vcpu(vcpu)->cpuid_cache.features_edx &
+				 HV_FEATURE_DEBUG_MSRS_AVAILABLE))))
 		return 1;
 
 	trace_kvm_hv_syndbg_set_msr(vcpu->vcpu_id,
@@ -351,7 +353,9 @@ static int syndbg_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
 {
 	struct kvm_hv_syndbg *syndbg = to_hv_syndbg(vcpu);
 
-	if (!kvm_hv_is_syndbg_enabled(vcpu) && !host)
+	if (unlikely(!host && (!kvm_hv_is_syndbg_enabled(vcpu) ||
+			       !(to_hv_vcpu(vcpu)->cpuid_cache.features_edx &
+				 HV_FEATURE_DEBUG_MSRS_AVAILABLE))))
 		return 1;
 
 	switch (msr) {
-- 
2.30.2


  parent reply	other threads:[~2021-04-13 12:28 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-13 12:26 [PATCH RFC 00/22] KVM: x86: hyper-v: Fine-grained access check to Hyper-V hypercalls and MSRs Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 01/22] asm-generic/hyperv: add HV_STATUS_ACCESS_DENIED definition Vitaly Kuznetsov
2021-04-15 14:14   ` Wei Liu
2021-04-15 15:33     ` Vitaly Kuznetsov
2021-04-16 10:31       ` Wei Liu
2021-04-13 12:26 ` [PATCH RFC 02/22] KVM: x86: hyper-v: Cache guest CPUID leaves determining features availability Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 03/22] KVM: x86: hyper-v: Honor HV_MSR_VP_RUNTIME_AVAILABLE privilege bit Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 04/22] KVM: x86: hyper-v: Honor HV_MSR_TIME_REF_COUNT_AVAILABLE " Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 05/22] KVM: x86: hyper-v: Honor HV_MSR_HYPERCALL_AVAILABLE " Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 06/22] KVM: x86: hyper-v: Honor HV_MSR_VP_INDEX_AVAILABLE " Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 07/22] KVM: x86: hyper-v: Honor HV_MSR_RESET_AVAILABLE " Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 08/22] KVM: x86: hyper-v: Honor HV_MSR_REFERENCE_TSC_AVAILABLE " Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 09/22] KVM: x86: hyper-v: Honor HV_MSR_SYNIC_AVAILABLE " Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 10/22] KVM: x86: hyper-v: Honor HV_MSR_SYNTIMER_AVAILABLE " Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 11/22] KVM: x86: hyper-v: Honor HV_MSR_APIC_ACCESS_AVAILABLE " Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 12/22] KVM: x86: hyper-v: Honor HV_ACCESS_FREQUENCY_MSRS " Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 13/22] KVM: x86: hyper-v: Honor HV_ACCESS_REENLIGHTENMENT " Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 14/22] KVM: x86: hyper-v: Honor HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE " Vitaly Kuznetsov
2021-04-13 12:26 ` Vitaly Kuznetsov [this message]
2021-04-13 12:26 ` [PATCH RFC 16/22] KVM: x86: hyper-v: Honor HV_STIMER_DIRECT_MODE_AVAILABLE " Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 17/22] KVM: x86: hyper-v: Honor HV_POST_MESSAGES " Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 18/22] KVM: x86: hyper-v: Honor HV_SIGNAL_EVENTS " Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 19/22] KVM: x86: hyper-v: Honor HV_DEBUGGING " Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 20/22] KVM: x86: hyper-v: Honor HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED bit Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 21/22] KVM: x86: hyper-v: Honor HV_X64_CLUSTER_IPI_RECOMMENDED bit Vitaly Kuznetsov
2021-04-13 12:26 ` [PATCH RFC 22/22] KVM: x86: hyper-v: Check access to HVCALL_NOTIFY_LONG_SPIN_WAIT hypercall Vitaly Kuznetsov

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